🔋 LiPo
Lithium-Polymer battery — the light, high-power rechargeable pack most modern RC uses.
Each cell is 3.7V nominal, 4.2V full, ~3.8V storage. Handle with care: never over-discharge, over-charge, or run a puffed pack.
What it actually does
Lithium-polymer packs are what almost every modern electric RC runs on, because they hold far more energy for their weight than the NiMH packs they replaced and they hold voltage up under load instead of sagging away. That steady voltage is why a LiPo car feels strong all the way to the end of a run rather than going soft after two minutes.
In practice
A pack is described by cell count and capacity: a "2S 5000mAh" pack is two cells in series, nominally 7.4V, holding 5000 milliamp-hours. Each cell is nominally 3.7V, fully charged at 4.2V. More cells means more voltage, which means more motor RPM and more heat — never fit a higher cell count than your ESC and motor are rated for.
Worth knowing
LiPo needs respect, not fear. Charge on a non-flammable surface, in a charging bag or metal tin, and stay in the room while it charges. Always balance-charge so the cells stay level with each other. Never charge a pack that is puffed, damaged or has been in a heavy crash, and let a hot pack cool to room temperature before charging it.
Common questions
How long do LiPo packs last?
Measured in charge cycles rather than months — a well-treated pack commonly stays useful for a few hundred cycles. Storing at the right voltage rather than full is the single biggest thing that extends that life.
Can I leave a LiPo charged overnight?
Leaving a pack sitting at full charge is what ages it fastest. If you are not running within a day or so, put it to storage charge instead.